Differentiation induction into adipocytes is used for confirmation of the undifferentiation ability of human somatic stem cells, research on metabolic syndromes and the like in differentiation-induced adipocytes, and other purposes.
Differentiation induction into adipocytes from human somatic stem cells and preadipocytes employs animal serum (such as fetal bovine serum or human serum). It is known that the component structure of animal serum has yet to be completely clarified, as well as capabilities such as the ability to induce differentiation into adipocytes vary depending on the origin of serum, the lot of product and the like. Thus, there is a problem that it is difficult to maintain the quality of adipocytes induced to differentiate under conditions of high serum concentration.
Conventionally, as methods for inducing the differentiation of somatic stem cells into adipocytes, there have been disclosed some methods such as a method using isobutylmethylxanthine, dexamethasone, insulin, and a thiazole derivative (such as rosiglitazone or pioglitazone) in an animal serum-containing culture medium (Non-patent Literature 1) and a method using isobutylmethylxanthine, dexamethasone, insulin, and an indole derivative (such as indomethacin) (Non-patent Literature 2). It is also known that the addition of biotin, prostaglandin, and pantothenic acid causes adipocyte differentiation.
Activation of RhoA is known to inhibit the induction of differentiation into adipocytes and promote the induction of differentiation into osteocytes (Non-patent Literature 3). Lysophosphatidic acid (LPA), which is lysophospholipid, is known as a substance that induces the RhoA activation. So far, there have been known no methods for improving the efficiency of differentiation into adipocytes by the addition of LPA serving to activate RhoA to a culture medium for inducing the differentiation of somatic stem cells into adipocytes.